CN114815243A

CN114815243A - Display device

Info

Publication number: CN114815243A
Application number: CN202210031593.2A
Authority: CN
Inventors: 李智元; 权载中; 金泳灿; 刘在镐
Original assignee: Samsung Display Co Ltd
Current assignee: Samsung Display Co Ltd
Priority date: 2021-01-19
Filing date: 2022-01-12
Publication date: 2022-07-29
Also published as: US20220229299A1; KR20220105234A

Abstract

A display device is provided. The display device includes: an optical combiner comprising a first surface, a second surface disposed at a first side of the first surface, and a third surface disposed at a second side of the first surface; a diffractive optical element disposed on the first surface of the optical combiner; a first display panel arranged on the second surface of the optical combiner and displaying a first color image; and a second display panel disposed on the third surface of the optical combiner and displaying a second color image.

Description

Display device

Cross Reference to Related Applications

This application claims priority and benefit of korean patent application No. 10-2021-0007461, filed on 19.1.2021 to the korean intellectual property office, the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure relates to a display device.

Background

With the development of technologies capable of realizing virtual reality, interest in display devices related thereto is increasing. Virtual reality may be realistically provided by a three-dimensional display device, such as a Head Mounted Display (HMD) or a Face Mounted Display (FMD), that a user can view very closely. Since the display device is placed in front of the eyes of the user, a screen effect in which lines are visible between pixels may occur in the case where the display device has a low resolution. This is a phenomenon in which the black matrix between pixels is enlarged and viewed through the lenses of the display device, and may be reduced as the resolution of the display device increases.

In a display device having a size that a user can wear on his/her head or face, it may be difficult or limited in achieving high resolution.

The above information disclosed in this background section is only for enhancement of understanding of the background, and therefore, it may contain information that may not constitute prior art that may be known to one of ordinary skill in the art.

Disclosure of Invention

Embodiments provide a high resolution display device.

The display device according to the embodiment may include: an optical combiner comprising a first surface, a second surface disposed at a first side of the first surface, and a third surface disposed at a second side of the first surface; a diffractive optical element disposed on the first surface of the optical combiner; a first display panel arranged on the second surface of the optical combiner and displaying a first color image; and a second display panel disposed on the third surface of the optical combiner and displaying a second color image.

The diffractive optical element may cause light providing the first color image and light providing the second color image to travel in a direction perpendicular to the first surface of the optical combiner.

The display screen of the first display panel may be parallel to the second surface of the optical combiner, and the display screen of the second display panel may be parallel to the third surface of the optical combiner.

The display device may further include a lens facing the first surface of the optical combiner.

A first distance between the display screen of the first display panel and the diffractive optical element may be equal to a second distance between the display screen of the second display panel and the diffractive optical element.

The focal length of the lens may be equal to a sum of a first distance between the display screen of the first display panel and the diffractive optical element and a distance between the diffractive optical element and the lens.

The optical combiner can include a fourth surface disposed between the second surface of the optical combiner and the third surface of the optical combiner. The display device may include a third display panel disposed on the fourth surface and displaying a third color image.

The fourth surface of the optical combiner may be parallel to the first surface of the optical combiner, and the display screen of the third display panel may be parallel to the fourth surface of the optical combiner.

The diffractive optical element may cause light providing the third color image to travel in a direction perpendicular to the first surface of the optical combiner.

The optical combiner can include a fourth surface disposed between the second surface of the optical combiner and the third surface of the optical combiner. The display device may include a third display panel disposed on the first surface of the optical combiner and displaying a third color image.

The optical combiner may have a cross-sectional shape that is substantially triangular or substantially trapezoidal.

The diffractive optical element may be attached, connected or coupled to the first surface of the optical combiner.

The diffractive optical element may be patterned on the first surface of the optical combiner.

The display device may further include an optical film disposed between the first display panel and the second surface of the optical combiner and between the second display panel and the third surface of the optical combiner.

When the angle formed by the first surface and the second surface is theta ₁ The angle formed by the first surface and the third surface is theta ₂ And when the width of the first color image is α, the width of the second color image is β, and the width of the diffractive optical element is x, satisfying: α ═ x cos θ ₁ ，β＝x coSθ ₂ 。

The display device according to the embodiment may include: an optical combiner comprising a first surface, a second surface disposed at a first side of the first surface, a third surface disposed at a second side of the first surface, and a fourth surface facing the first surface; a diffractive optical element disposed on the first surface of the optical combiner; a first display panel arranged on the second surface of the optical combiner and displaying a first color image; a second display panel arranged on the third surface of the optical combiner and displaying a second color image; and a third display panel disposed on the first surface of the optical combiner or the fourth surface of the optical combiner to display a third color image.

The display device may further include a lens adjacent to the first surface of the optical combiner, and the third display panel may be disposed on the fourth surface of the optical combiner.

The display device may further include a lens adjacent to the fourth surface of the optical combiner, the third display panel may be disposed on the first surface of the optical combiner, and the diffractive optical element may be disposed between the third display panel and the optical combiner.

The optical combiner may have a substantially trapezoidal cross-sectional shape, and the first surface of the optical combiner and the fourth surface of the optical combiner may be parallel to each other.

When the angle formed by the first surface and the second surface is theta ₁ The angle formed by the first surface and the third surface is theta ₂ And the width of the first color image is α, the width of the second color image is β, the width of the third color image is γ, and the width of the diffractive optical element is x, satisfy:

α＝x cosθ ₁ ，β＝x cosθ ₂ ，γ＝x。

according to the embodiment, by combining monochrome images, the resolution of the display device can be increased and the luminance can be improved. According to embodiments, there are other advantageous effects that can be identified throughout the specification.

Drawings

The above and other aspects and features of the present disclosure will become more apparent by describing in detail embodiments of the present disclosure with reference to the attached drawings.

Fig. 1 shows a schematic structure and image superimposition of a display device according to an embodiment.

Fig. 2 illustrates a schematic front view showing a structure of a 3D image display device according to an embodiment.

Fig. 3 shows a schematic side view illustrating the structure of a display device according to an embodiment.

Fig. 4, 5, and 6 illustrate a design method of a display device according to an embodiment.

Fig. 7 and 8 each show a schematic side view showing the structure of a display device according to the embodiment.

Fig. 9 and 10 illustrate a design method of a display device according to an embodiment.

Fig. 11 and 12 illustrate a 3D image display device according to an embodiment.

Detailed Description

The present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown.

Further, the sizes and thicknesses of constituent elements shown in the drawings are arbitrarily given for better understanding and convenience of description.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In the description and claims, the term "and/or" is intended to include any combination of the terms "and" or "for purposes of meaning and explanation thereof. For example, "a and/or B" can be understood to mean "A, B, or a and B". The terms "and" or "may be used in a combined or separated sense and may be understood to be equivalent to" and/or ".

In the specification and claims, for the purpose of their meaning and interpretation, the phrase "at least one of … …" is intended to include the meaning of "at least one selected from the group … …". For example, "at least one of a and B" can be understood to mean "A, B, or a and B".

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure.

For convenience in description, spatially relative terms "below," "beneath," "lower," "above," "upper," and the like may be used herein to describe one element or component's relationship to another element or component as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, in the case where a device shown in the drawings is turned over, a device positioned "below" or "beneath" another device may be placed "above" the other device. Thus, the illustrative term "below" may include both lower and upper positions. The device may also be oriented in other directions, and the spatially relative terms may thus be interpreted differently depending on the orientation.

The terms "overlap" or "overlapping" mean that the first object may be above or below the second object or to the side of the second object, and vice versa. Further, the term "overlap" may include stacking, facing or facing, extending over … …, covering or partially covering, or any other suitable term that would be appreciated and understood by one of ordinary skill in the art.

When an element is described as "non-overlapping" or "to be non-overlapping" with another element, this may include the elements being spaced apart from each other, offset from each other, or separate from each other, or any other suitable terminology as will be appreciated and understood by one of ordinary skill in the art.

The terms "facing" and "facing" mean that a first element can be directly or indirectly opposite a second element. In the case where the third element is interposed between the first element and the second element, the first element and the second element may be understood as being indirectly opposite to each other, although still facing each other.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

Furthermore, unless explicitly described to the contrary, the word "comprising" and variations such as "comprises" or "comprising," including "and/or" including, "having (has)" and/or "having (having)" and variations thereof, when used in this specification, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

Further, in the specification, "connected" or "coupled" means that two or more components are not only directly connected or coupled, but also two or more components may be indirectly connected or coupled, physically connected or coupled, and electrically connected or coupled through other components, or "connected" or "coupled" may be referred to by different names depending on positions or functions, but may include each of a plurality of portions which may be substantially integrated with each other.

The phrase "in a plan view" means that the object is viewed from the top, and the phrase "in a schematic cross-sectional view" means that the object is viewed from the side in a vertically cut cross-section.

As used herein, "about" or "approximately" includes the stated values and is meant to be within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, given the measurement in question and the error associated with the particular number of measurements (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ± 30%, ± 20%, ± 10% or ± 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1 shows a schematic structure and image superimposition of a display device 10 according to an embodiment.

The display device 10 may include an optical combiner 100, a diffractive optical element 200,

display panels

310, 320, and 330, and a lens 400.

The optical combiner 100 may provide an optical path between the

display panels

310, 320, and 330 and the diffractive optical element 200. The optical combiner 100 is a medium that transmits an image displayed on each of the

display panels

310, 320, and 330 to the diffractive optical element 200. Optical combiner 100 may be an optical element, such as a prism or a lens. By way of non-limiting example, optical combiner 100 may be formed from a transparent material, such as glass or plastic. Optical combiner 100 may be formed entirely of the same material or similar materials. Optical combiner 100 may have a generally polygonal column shape (e.g., a generally triangular prism or a generally quadrangular prism).

The diffractive optical element 200 can alter the optical path provided by the optical combiner 100. The diffractive optical element 200 may refract, transmit, or reflect light to direct light in a direction. For example, the diffractive optical element 200 may refract light forming an image displayed by the

display panels

310 and 320 toward the lens 400, and may transmit light forming an image displayed by the display panel 330 toward the lens 400. The diffractive optical element 200 may emit light (in a direction towards the lens 400) incident at an angle to the front face. The diffractive optical element 200 may be a diffraction grating. The diffractive optical element 200 can be attached to, connected to, or coupled to the optical combiner 100, or can be patterned on a surface of the optical combiner 100.

Each of the

display panels

310, 320, and 330 may be a monochrome display panel capable of providing an image displayed in one of the primary colors. The primary colors may include red, green, and blue. The

display panels

310, 320, and 330 may provide images of different colors. For example, the

display panels

310, 320, and 330 include a first display panel 310 for displaying the first color image IM1, a second display panel 320 for displaying the second color image IM2, and a third display panel 330 for displaying the third color image IM 3. The first display panel 310 may include only first color pixels, the second display panel 320 may include only second color pixels, and the third display panel 330 may include only third color pixels. The first color may be green, the second color may be red, and the third color may be blue, but the color is not limited thereto. For example, the first color may be one of red, green, and blue, the second color may be one of red, green, and blue other than the first color, and the third color may be one of red, green, and blue other than the first color and the second color.

There is no limitation on the type of display panel included in the display device 10. For example, the

display panels

310, 320, and 330 may be emission display panels including organic light emitting diodes or inorganic light emitting diodes. As an example, the

display panels

310, 320, and 330 may be liquid crystal display panels.

The lens 400 may magnify an image provided through the diffractive optical element 200, thereby improving the sense of immersion and presence of a user. In the case where the image is magnified by the lens 400, the black matrix between the pixels is also magnified, so it may be advantageous to increase the resolution of the display device 10 in order to reduce the screening effect that may occur where lines are visible between the pixels.

The monochrome images IM1, IM2, and IM3 displayed by the

respective display panels

310, 320, and 330 are combined in the diffractive optical element 200 by the optical combiner 100 to be displayed as a multicolor image. The first color image IM1 displayed by the first display panel 310, the second color image IM2 displayed by the second display panel 320, and the third color image IM3 displayed by the third display panel 330 may be guided to the diffractive optical element 200 by the optical combiner 100, and may be superimposed in the diffractive optical element 200 to provide a multicolor image. As such, in the case of displaying an image by combining the monochrome images IM1, IM2, and IM3, the resolution of the display device can be increased as compared with the case of displaying a plurality of colors on a single display panel. For example, the resolution of the display device may be increased by about three times as compared to displaying an image by arranging all of the first color pixels, the second color pixels, and the third color pixels on a single display panel.

The optical combiner 100, the diffractive optical element 200, the

display panels

310, 320, and 330, and the lens 400 may be fixed to an optical holder (not shown) to hold their respective positions.

One of ways to express a 3D image is a method using binocular disparity, which is the largest factor to recognize a 3D effect. For example, in a case where different 2D images are respectively provided to the left and right eyes and an image provided to the left eye (hereinafter, referred to as a "left eye image") and an image provided to the right eye (hereinafter, referred to as a "right eye image") are transmitted to the brain, the left eye image and the right eye image are fused by the brain to be recognized as a 3D image having depth perception. The 3D image display device may include a left eye display device 10L and a right eye display device 10R, and the left eye display device 10L and the right eye display device 10R provide a left eye image and a right eye image having parallax, respectively, so that the user feels the 3D effect.

The left-eye display device 10L may include an optical combiner 100L, a diffractive optical element 200L,

display panels

310L and 320L, and a lens 400L. The right-eye display device 10R may include an optical combiner 100R, a diffractive optical element 200R,

display panels

310R and 320R, and a lens 400R. The left-eye display device 10L and the right-eye display device 10R may be fixed to a single optical holder or separate optical holders.

In the case where the left-eye display device 10L and the right-eye display device 10R each include two display panels (310L and 320L; 310R and 320R), the left-eye display device 10L and the right-eye display device 10R may each include a display panel for displaying the same color among the primary colors. For example, the

display panels

310L and 320L of the left-eye display device 10L may display a red image and a green image, respectively, and the

display panels

310R and 320R of the right-eye display device 10R may display a blue image and a green image, respectively. Even in the case where the left-eye display device 10L and the right-eye display device 10R each display an image in which two monochrome images are superimposed on each other, the user can combine the left-eye image and the right-eye image to recognize the images as a multicolor image. Unlike as shown, the left-eye display device 10L and the right-eye display device 10R may each include three display panels that display monochrome images of different colors.

The left-eye display device 10L and the right-eye display device 10R may have a difference in color of the images provided by the

display panels

310L and 320L and 310R and 320R, but they may be identical in structure. Hereinafter, the left-eye display device 10L and the right-eye display device 10R will be described as the display devices 10 without distinction. For example, the display device 10 described herein may be a left eye display device 10L or a right eye display device 10R.

Fig. 3 shows a schematic side view illustrating the structure of the display device 10 according to the embodiment. Fig. 3 shows an example in which one display device 10 may include two

display panels

310 and 320.

Optical combiner 100 may have a generally triangular cross-sectional shape. Optical combiner 100 may have a generally triangular prism shape. The optical combiner 100 may include a first surface S1, a second surface S2, and a third surface S3.

The diffractive optical element 200 may be disposed or arranged on the first surface S1 of the optical combiner 100. The diffractive optical element 200 may be attached or disposed to or coupled to the first surface S1, or may be patterned on the first surface S1. The first surface S1 may be the largest of the three surfaces S1, S2, and S3 of the optical combiner 100, but the disclosure is not limited thereto.

The first display panel 310 may be disposed or arranged on the second surface S2, and the second display panel 320 may be disposed or arranged on the third surface S3. The display screen of the first display panel 310 may be parallel to the second surface S2, and the display screen of the second display panel 320 may be parallel to the third surface S3. The display screen of the first display panel 310 may be spaced apart from the second surface S2 by a space, or may be in contact with the second surface S2. The display screen of the second display panel 320 may be spaced apart from the third surface S3 by a space, or may be in contact with the third surface S3.

Herein, the display screen means a surface on each of the

display panels

310 and 320 on which the images IM1 and IM2 can be displayed, and the display screen may have a width in a horizontal direction and/or a vertical direction. The size of the display screen of the first display panel 310 may correspond to the size of the first color image IM1, and the size of the display screen of the second display panel 320 may correspond to the size of the second color image IM 2. The first color image IM1 and the second color image IM2 may be displayed on the display screen of the first display panel 310 and the display screen of the second display panel 320, respectively, and they are shown in the second surface S2 and the third surface S3 of the optical combiner 100 for convenience.

The optical films OF, such as microlens array films, may be positioned or disposed between the first display panel 310 and the second surface S2 and between the second display panel 320 and the third surface S3.

The lens 400 may be positioned or disposed adjacent to the first surface S1 of the optical combiner 100. The lens 400 may be separated from the first surface S1 in consideration of the focal length.

The first color image IM1 displayed by the first display panel 310 and the second color image IM2 displayed by the second display panel 320 may be guided to the diffractive optical element 200 by the optical combiner 100 and may be superimposed on the diffractive optical element 200. The superimposed first color image IM1 and second color image IM2 may be output by the diffractive optical element 200 toward the lens 400, and the user may view the superimposed image of the first color image IM1 and second color image IM2 (e.g., an image displayed by combining the first color image IM1 and second color image IM 2) through the lens 400.

Fig. 4, 5, and 6 illustrate a design method of the display device 10 according to the embodiment.

Referring to FIG. 4 for a design of optical combiner 100, a cross-section of optical combiner 100 in display device 10 shown in FIG. 3, which includes two

display panels

310 and 320, is shown. A first distance d1 between the first color image IM1 and the first surface S1 and a second distance d2 between the second color image IM2 and the first surface S1 may be the same so as to superimpose the first color image IM1 and the second color image IM2 on the first surface S1 on which the diffractive optical element 200 may be disposed or arranged. In the present specification, unless otherwise stated, the distance means a distance between centers of constituent elements.

The vertex at which the first surface S1 and the second surface S2 intersect is P, the vertex at which the first surface S1 and the third surface S3 intersect is Q, the intersection point of the first color image IM1 and the second color image IM2 on the first surface S1 is M, and the angle formed between the first surface S1 and the second surface S2 is θ ₁ And an angle formed between the first surface S1 and the third surface S3 is θ ₂ In this case, the following equation can be established.

d ₁ ＝d ₂ ＝a tanθ ₁ ＝b tanθ ₂

In the above equation, a ₁ Indicating the distance between the vertex P and the intersection M, b ₁ Indicates the distance between the vertex Q and the intersection point M, a indicates the distance between the first color image IM1 and the vertex P, and b indicates the distance between the second color image IM2 and the vertex Q. The intersection point M may correspond to the center of the diffractive optical element 200.

θ ₁ And theta ₂ May vary depending on, for example, the period of the lattice in the diffractive optical element 200, the pattern structure. Light has different refractive indices depending on its wavelength, and thus θ ₁ And theta ₂ May be different. Theta ₁ And theta ₂ Based on diffractive optical elementsThe characteristics of the piece 200 and the colors of the monochromatic images IM1 and IM2 provided by the

display panels

310 and 320. At the moment of determining theta ₁ And theta ₂ In this case, the optimal positions of the diffractive optical element 200 and the

display panels

310 and 320 on the optical combiner 100 can be determined according to the above equation.

E.g. at theta ₁ And theta ₂ Determined to be about 45 ° and about 59.67 °, respectively, a may be about 30.80mm, b may be about 18.01mm, a ₁ May be about 43.55mm, and b ₁ May be about 35.68 mm. In the case where the first color image IM1 is a green image and the second color image IM2 is a red image, θ ₂ May be greater or less than theta ₁ 。θ ₁ And theta ₂ Each value in (b) and the magnitude relationship therebetween may depend on the characteristics of the diffractive optical element 200.

A method of designing the size of each of the display panels 310 and 320 (more precisely, the size of the display screen of each of the display panels 310 and 320) will be described with reference to fig. 5.

In the case where the width of the first color image IM1 corresponding to the width of the display screen of the first display panel 310 is α, the width of the second color image IM2 corresponding to the width of the display screen of the second display panel 320 is β, and the width of the diffractive optical element 200 is x, the following equation can be established.

a′＝a _n cosθ ₁ ，b′=b _n cosθ ₂

α＝x cosθ ₁ ，β＝x cosθ ₂

0＜β＜2b

In the above equation, a 'indicates the distance between the first color image IM1 and the vertex P, b' indicates the distance between the second color image IM2 and the vertex Q, a _n Indicates the distance between the diffractive optical element 200 and the apex P, and b _n Indicating the distance between the diffractive optical element 200 and the vertex Q.

E.g., about 20mm at x, θ ₁ Is about 45 ° and θ ₂ At about 59.67 deg., alpha is about 14.14mm and beta is about 10.09 mm. As such, each of the display panels 310 and 320The width of the display screen may depend on the two angles θ of the optical combiner 100 ₁ And theta ₂ And the width x of the diffractive optical element 200. The width x of the diffractive optical element 200 may correspond to or approximately correspond to the width of the image area provided by the diffractive optical element 200.

Referring to FIG. 6, when θ ₂ Greater than theta ₁ When b is _n In the case of 0, it is possible to minimize the size of the optical combiner 100. a is _n The reason for being larger than 0 is because the first distance d1 between the first color image IM1 and the diffractive optical element 200 is the same as the second distance d2 between the second color image IM2 and the diffractive optical element 200. On the contrary, at θ ₁ Greater than theta ₂ By design a _n It is possible to minimize the size of optical combiner 100 to 0.

The respective distances from the

display panels

310 and 320 to the lens 400 and the focal length of the lens 400 may be designed to be the same in order to increase image clarity. As a result, the focal length of the lens 400 is equal to the first distance d1 between the first color image IM1 and the diffractive optical element 200 + the distance between the diffractive optical element 200 and the lens 400 is equal to the second distance d2 between the second color image IM2 and the diffractive optical element 200 + the distance between the diffractive optical element 200 and the lens 400. Herein, the first distance d1 may correspond to a distance between the display screen of the first display panel 310 and the diffractive optical element 200, and the second distance d2 may correspond to a distance between the display screen of the second display panel 320 and the diffractive optical element 200.

Fig. 7 and 8 each show a schematic side view showing the structure of a display device according to the embodiment. Fig. 7 and 8 illustrate an example in which one display apparatus 10 may include three

display panels

310, 320, and 330.

Referring to fig. 7, the optical combiner 100 may have a substantially trapezoidal sectional shape. Optical combiner 100 may have a generally quadrangular prism shape. Optical combiner 100 may include a first surface S1, a second surface S2, a third surface S3, and a fourth surface S4. The first surface S1 and the fourth surface S4 may face each other, and may be parallel. The first surface S1 may be the largest among the four surfaces S1, S2, S3, and S4 of the optical combiner 100, but the disclosure is not limited thereto.

The diffractive optical element 200 may be disposed or arranged on the first surface S1 of the optical combiner 100. The diffractive optical element 200 may be attached or disposed to or coupled to the first surface S1, or may be patterned on the first surface S1.

The first display panel 310 may be disposed or arranged on the second surface S2, the second display panel 320 may be disposed or arranged on the third surface S3, and the third display panel 330 may be disposed or arranged on the fourth surface S4. The display screen of the first display panel 310 may be parallel to the second surface S2, the display screen of the second display panel 320 may be parallel to the third surface S3, and the display screen of the third display panel 330 may be parallel to the fourth surface S4. The display screen of the first display panel 310 may be spaced apart from the second surface S2 by a space, or may be in contact with the second surface S2. The display screen of the second display panel 320 may be spaced apart from the third surface S3 by a space, or may be in contact with the third surface S3. The display screen of the third display panel 330 may be spaced apart from the fourth surface S4 by a space, or may be in contact with the fourth surface S4. The optical films OF, such as microlens array films, may be positioned or arranged between the first display panel 310 and the second surface S2, between the second display panel 320 and the third surface S3, and between the third display panel 330 and the fourth surface S4.

The lens 400 may be positioned or disposed adjacent to the first surface of the optical combiner 100 and the diffractive optical element 200. The lens 400 may be separated from the first surface S1 in consideration of the focal length.

The first color image IM1 displayed by the first display panel 310, the second color image IM2 displayed by the second display panel 320, and the third color image IM3 displayed by the third display panel 330 may be guided to the diffractive optical element 200 by the optical combiner 100, and may be superimposed in the diffractive optical element 200. The diffractive optical element 200 can reflect the first color image IM1 and the second color image IM2, and can transmit the third color image IM 3. The superimposed first color image IM1, second color image IM2, and third color image IM3 may be output by the diffractive optical element 200 toward the lens 400, and the user may view the superimposed images of the first color image IM1, second color image IM2, and third color image IM3 through the lens 400.

The display device 10 shown in fig. 8 may have a structure in which the optical combiner 100 in the display device 10 shown in fig. 7 is inverted. In the case of describing the difference from the display device 10 shown in fig. 7, the diffractive optical element 200 may be disposed or arranged on the first surface S1 of the optical combiner 100, and the third display panel 330 may also be disposed or arranged on the first surface S1. The diffractive optical element 200 may be positioned or arranged between the third display panel 330 and the optical combiner 100. The lens 400 may be positioned or disposed adjacent to the fourth surface S4.

The first color image IM1 and the second color image IM2 may be guided to the diffractive optical element 200 by the optical combiner 100, and the first color image IM1, the second color image IM2, and the third color image IM3 may be superimposed in the diffractive optical element 200. The diffractive optical element 200 can reflect the first color image IM1 and the second color image IM2 at an angle (e.g., in a direction perpendicular or substantially perpendicular to the first surface S1) and can transmit the third color image IM 3. The superimposed first, second, and third color images IM1, IM2, and IM3 may be directed toward the lens 400 through the diffractive optical element 200, and a user may view the superimposed images of the first, second, and third color images IM1, IM2, and IM3 through the lens 400.

Fig. 9 and 10 illustrate a design method of the display device 10 according to the embodiment.

Referring to FIG. 9 regarding the design of optical combiner 100, a cross-section of optical combiner 100 in display device 10 shown in FIG. 7, which includes three

display panels

310, 320, and 330, is shown. The first distance d1 between the first color image IM1 and the first surface S1, the second distance d2 between the second color image IM2 and the first surface S1, and the third distance d3 between the third color image IM3 and the first surface S1 may be the same so that the first color image IM1, the second color image IM2, and the third color image IM3 are superimposed on the first surface S1 on which the diffractive optical element 200 is disposed.

Similar to the design of the optical combiner 100 in the display device 10 comprising two

display panels

310 and 320, in the first tableThe vertex at which the face S1 and the second surface S2 intersect is P, the vertex at which the first surface S1 and the third surface S3 intersect is Q, the intersection point of the first color image IM1 and the second color image IM2 on the first surface S1 is M, and the angle formed between the first surface S1 and the second surface S2 is θ ₁ And an angle formed between the first surface S1 and the third surface S3 is theta ₂ In the case of (2), the following equation can be satisfied.

d ₁ ＝d ₂ ＝d ₃ ＝a tanθ ₁ ＝b tanθ ₂

θ ₁ And theta ₂ May vary depending on, for example, the period of the lattice in the diffractive optical element 200, the pattern structure. Light has different refractive indices depending on its wavelength, and thus θ ₁ And theta ₂ May be different. θ can be determined according to the characteristics of the diffractive optical element 200 and the colors of the monochromatic images IM1 and IM2 provided by the first display panel 310 and the second display panel 320 ₁ And theta ₂ . At the moment of determining theta ₁ And theta ₂ In this case, the optimal positions of the diffractive optical element 200 and the first and

second display panels

310 and 320 on the optical combiner 100 may be determined according to the above equation. The position of the third display panel 330 may be optimized by making the third distance d3 equal to the first distance d1 and the second distance d 2.

A method of designing the size of each of the

display panels

310, 320, and 330 (more precisely, the size of the display screen of each of the

display panels

310, 320, and 330) will be described with reference to fig. 10.

In the case where the width of the first color image IM1 corresponding to the width of the first display screen of the first display panel 310 is α, the width of the second color image IM2 corresponding to the width of the second display screen of the second display panel 320 is β, and the width of the diffractive optical element 200 is x, the following equations can be established.

a′＝a _n cosθ ₁ ，b′=b _n cosθ ₂

α＝x cosθ ₁ ，β＝x cosθ ₂

0＜β＜2b

The widths of the display screens of the first display panel 310 and the second display panel 320 may depend on two angles θ of the optical combiner 100 ₁ And theta ₂ And the width x of the diffractive optical element 200. Since the third display panel 330 is parallel to the diffractive optical element 200, the width γ of the display screen of the third display panel 330 may be the same as the width x of the diffractive optical element 200. The width x of the diffractive optical element 200 corresponds to the width of the image area provided by the diffractive optical element 200.

The respective distances from the

display panels

310, 320, and 330 to the lens 400 and the focal length of the lens 400 may be designed to be the same in order to increase image clarity. As a result, the focal length of the lens 400 is equal to the first distance d1 between the first color image IM1 and the diffractive optical element 200 + the distance between the diffractive optical element 200 and the lens 400 is equal to the second distance d2 between the second color image IM2 and the diffractive optical element 200 + the distance between the diffractive optical element 200 and the lens 400 is equal to the third distance d3 between the third color image IM3 and the diffractive optical element 200 + the distance between the diffractive optical element 200 and the lens 400. Herein, the first distance d1 may correspond to a distance between the display screen of the first display panel 310 and the diffractive optical element 200, the second distance d2 may correspond to a distance between the display screen of the second display panel 320 and the diffractive optical element 200, and the third distance d3 may correspond to a distance between the display screen of the third display panel 330 and the diffractive optical element 200.

Fig. 11 and 12 illustrate a 3D image display device according to an embodiment.

Fig. 11 generally illustrates a 3D image display device, and fig. 12 illustrates an internal structure of the display device 10 by removing a portion of the holder 500.

Referring to fig. 11, the 3D image display device may include a left-eye display device 10L and a right-eye display device 10R that may form a pair. The left-eye display device 10L and the right-eye display device 10R may be separate from or integrated with each other.

Referring to fig. 12, the display device 10 may include a holder 500, the optical combiner 100 accommodated in the holder 500, a diffractive optical element,

display panels

310 and 320, and a lens 400. The diffractive optical element may be disposed or arranged on the long side of the optical combiner 100. The

display panels

310 and 320 may be positioned up and down as shown, but may be positioned side-to-side or tilted. The monochromatic images displayed by the

display panels

310 and 320 may be superimposed by the optical combiner 100 and the diffractive optical element to be displayed as a multicolor image, and may be finally provided to a user through the lens 400.

While the disclosure has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the disclosure and the appended claims.

Claims

1. A display device, comprising:

an optical combiner comprising:

a first surface;

a second surface disposed at a first side of the first surface; and

a third surface disposed at a second side of the first surface;

a diffractive optical element disposed on the first surface of the optical combiner;

a first display panel arranged on the second surface of the optical combiner and displaying a first color image; and

a second display panel disposed on the third surface of the optical combiner and displaying a second color image.

2. The display device of claim 1, wherein the diffractive optical element causes light providing the first color image and light providing the second color image to travel in a direction perpendicular to the first surface of the optical combiner.

3. The display device according to claim 1,

the display screen of the first display panel is parallel to the second surface of the optical combiner, and

the display screen of the second display panel is parallel to the third surface of the optical combiner.

4. The display device according to claim 1, further comprising:

a lens facing the first surface of the optical combiner.

5. The display device of claim 4, wherein a first distance between the display screen of the first display panel and the diffractive optical element is equal to a second distance between the display screen of the second display panel and the diffractive optical element.

6. The display device of claim 5, wherein a focal length of the lens is equal to a sum of the first distance and a distance between the diffractive optical element and the lens.

7. The display device according to claim 1,

the optical combiner includes a fourth surface disposed between the second surface of the optical combiner and the third surface of the optical combiner, and

the display device includes a third display panel that is arranged on the fourth surface and displays a third color image.

8. The display device according to claim 7,

the fourth surface of the optical combiner is parallel to the first surface of the optical combiner, and

the display screen of the third display panel is parallel to the fourth surface of the optical combiner.

9. The display device of claim 7, wherein the diffractive optical element causes light providing the third color image to travel in a direction perpendicular to the first surface of the optical combiner.

10. The display device according to claim 1,

the display device includes a third display panel arranged on the first surface of the optical combiner and displaying a third color image.

11. The display device of claim 1, wherein the optical combiner has a triangular or trapezoidal cross-sectional shape.

12. The display device of claim 1, wherein the diffractive optical element is attached, connected, or coupled to the first surface of the optical combiner.

13. The display device of claim 1, wherein the diffractive optical element is patterned on the first surface of the optical combiner.

14. The display device according to claim 1, further comprising:

an optical film disposed between the first display panel and the second surface of the optical combiner and between the second display panel and the third surface of the optical combiner.

15. The display device according to claim 1,

when the angle formed by the first surface and the second surface is theta ₁ An angle formed by the first surface and the third surface is theta ₂ And a width of the first color image is α, a width of the second color image is β, and a width of the diffractive optical element is x, satisfy:

α＝x cosθ ₁ ，β＝x cosθ ₂ 。